1. Field of the Invention
The present invention relates to a circular polarization antenna structure and a method for manufacturing the same, and particularly relates to a circular polarization antenna structure with a dual-layer ceramic and a method for manufacturing the same.
2. Description of Related Art
Due to the development of communication technology, a lot of electronic products have been developed that use wireless communication technology, such as cell phones, wireless Internet devices, and personal digital assistants (PDAs), etc. The requirements demanded by consumers for the wireless communication devices has become higher and higher, namely in terms of the appearance and dimensions of the devices. For cell phones, the receiving frequency has developed from a single frequency, to two, then three, and now four frequencies. Consumers also prefer cell phones having the characteristics of an appealing appearance, small dimensions, light weight, and portability.
Because SDARS (Satellite Digital Audio Radio Service) can receive high quality audio signals and can be applied to many radio stations, SDARS is popular in USA. At present, the bandwidth of SDARS is serviced by two system operators (SIRIUS and XM), who share the bandwidth range to equal parts.
Moreover, SDARS mostly uses a circular polarization antenna with single-layer substrates or uses a copper foil to paste on the circular polarization antenna with single-layer substrates by foamed plastic. However, the zenith gain of the circular polarization antenna with single-layer substrates is low. In addition, the copper foil pasted on the on the circular polarization antenna by the foamed plastic is compressed easily by external force, so the conductivity of the circular polarization antenna with single-layer substrates is unstable. Furthermore, SIRIUS and XM are merged in order to provide high frequency and high zenith gain, so that a new circular polarization antenna needs to be created to achieve corresponding frequency and zenith gain.